The comparative effectiveness (CE) of screening endoscopy in patients with GERD symptoms (vs. no screening) or among different surveillance strategies (frequency, intensity) is unclear due to lack of strong evidence-based findings for GERD or Barrett's esophagus (BE) population at risk of EA. Furthermore, it is unclear if patients or providers will accept or embrace any of these strategies irrespective of their effectiveness. Screening and surveillance is expensive and has risks. Therefore, it is imperative to establish the CE as well as patient- and provider- risk perceptions, outcome expectancies and affective responses of these practices to support or refute the validity of expert recommendations (and clinical policies that derive from them). There have been no cohort studies of at risk populations addressing the CE of screening or surveillance endoscopy, and there have been no in depth studies to examine determinants of decision making in screening or surveillance. Our proposed study has the following Aims. Aim #1. To compare the risk (detection rate) and outcomes (stage, treatment, survival) of EA among patients undergoing different intensity of screening (vs. none) and surveillance endoscopy (none, once every 2 yrs, once every 3 yrs). We will explain the effect of screening and surveillance endoscopy on EA by estimating likelihood of: 1) early stage EA;2) curative treatments for EA;and 3) mortality. Aim #2. To identify predictors of desired outcomes of EA (low incidence and low EA mortality). Potential predictors include demographic features (e.g., age), GERD features (e.g., duration), interventions (e.g., PPI, ASA/NSAID;fundoplication;ablation), and other BE risk factors (e.g., obesity, smoking). Aim #3. To elicit patients'and physicians'risk perceptions, outcome expectancies and affective responses to alternative endoscopic screening and surveillance strategies. Data from these in-depth qualitative interviews will be used to inform the design of potential interventions to enhance the dissemination and implementation of the key findings from this CE research. We propose a study with a mixed methods approach where we will (1) use secondary databases (VA and VA- Medicare linked datasets for 2000-08) to examine CE of screening and surveillance in an observational study cohort (an estimated 100,000 patients with GERD, 15,000-20,000 with BE, and 2000-3000 with EA);(2) conduct a detailed structured electronic medical record (EMR) review on a national sample of patients using VA electronic medical records to verify all EA cases, identify cancer stage, cancer-targeted therapy, and validate the screening and surveillance endoscopy;and (3) generate qualitative data from in depth interviews on patient and provider preferences and rational and behavioral utilities to explain some of the cohort study findings and inform the recommendations resulting from this research. PUBLIC HEALTH RELEVANCE: The benefits of performing endoscopy in patients with gastroesophageal reflux is unclear or with Barrett's esophagus. This study proposed to compare different practices of performing endoscopy (none, once a year, once every two years, etc.), and evaluate the benefit of these practices on early detection of esophageal cancer, as well as treatment and survival of patients with esophageal cancer.